Ok this is a problem that has affected my car for about two years now. I installed heads, injectors, cam etc. at once and the car has never run right since. I'll tell you what I've tried and you guys suggest from there.
First my list of mods: (Items with a * by them were installed right before the problem)
This is an '86GT with 91 Shortblock.
Trickflow Track heat heads *
TFS stage 1 cam*
24lb injectors*
76mm C and L *
70MM edelbrock TB*
Cobra intake
K and N
Mac Long tubes
Mac H pipe
MSD 6AL*
Holley Laser Shot Coil*
Scorpion 1.72 rockers*
255LPH holley Fuel pump
Crane adjustable FPR (looks like a stock one. are these junk?)
and the rest are drivetrain mods that dont matter.
O.K. now, Here's the problem. Whenever I drive the car after I start and warm it part throttle operation is mush. It feels like it is missing or something is holding back the power. As you roll into the throttle its crappy until u hit a certain spot and then it clears up instantly and accelerates hard. WOT it runs well too but still doesnt feel 100%. Ok here's the weird part. I can be rolling down the road right after this happens and turn the key off (while im rolling) and then right back on and roll into the gas and it runs like a scalded dog. It runs like I feel like it should. Perfectly smooth, all kinds of part throttle power and WOT feels great. I drive it for a little bit more and then BAM part throttle sucks again unless I turn the key off and on again.
Here's what I've tried:
New O2's (twice)
New MAF electronics (twice)
New MAP off mass air car (or BAP)
New TPS (twice)
New Fuel Pump
New FP filter
New ground strap
New 5 speed computer from advanced auto and an A9P auto computer
That's all I can remember right now.
Ok it seems like an electrical problem by the nature of me turning it off and on and it running fine. Here's some things I had questions about
#1: I rebuilt my tranny and for some reason put a top plate on the T-5 that didn't have the sensor on top. (not the reverse switch) The connector for it is just hanging under the car not being used. Now I'm not sure of the function of this sensor but I heard that it can cause similar problems if not connected or if the voltage isn't right.
#2 I heard that the B.O.O. switch can cause similar problems. (again I know this sounds crazy but very experienced people have told me this)
#3 My speedo gear keeps getting shredded (wrong one in tranny) so do u think it's because the speedo drive isn't turning? (i beleive i tried this once by putting a new one in and it didnt work)
#4 Should i try and find an original 5 speed ecu? Im pretty sure that A9p should work.
#5 Should I try a Pro-M meter?
#6 could I have gotten a bum injector that sticks or something until its de-energized by turning the key off and it runs fine until it sticks again?
#7 The ground that looks like it comes out of the injector harness; is that the injector ground or what?I have aluminum heads and it is grounded to them. (big ring connector)
I'm sure I can think of more later but if you guys could offer suggestions so far i'd greatly apprecitate it. I am sorrythis is my first post and it's so long but as you can see I've tried almost everything and I am at my wits end. this problem has stumped some of the best in the business so far.. Any help PLEEAASSEEE!!!?
First my list of mods: (Items with a * by them were installed right before the problem)
This is an '86GT with 91 Shortblock.
Trickflow Track heat heads *
TFS stage 1 cam*
24lb injectors*
76mm C and L *
70MM edelbrock TB*
Cobra intake
K and N
Mac Long tubes
Mac H pipe
MSD 6AL*
Holley Laser Shot Coil*
Scorpion 1.72 rockers*
255LPH holley Fuel pump
Crane adjustable FPR (looks like a stock one. are these junk?)
and the rest are drivetrain mods that dont matter.
O.K. now, Here's the problem. Whenever I drive the car after I start and warm it part throttle operation is mush. It feels like it is missing or something is holding back the power. As you roll into the throttle its crappy until u hit a certain spot and then it clears up instantly and accelerates hard. WOT it runs well too but still doesnt feel 100%. Ok here's the weird part. I can be rolling down the road right after this happens and turn the key off (while im rolling) and then right back on and roll into the gas and it runs like a scalded dog. It runs like I feel like it should. Perfectly smooth, all kinds of part throttle power and WOT feels great. I drive it for a little bit more and then BAM part throttle sucks again unless I turn the key off and on again.
Here's what I've tried:
New O2's (twice)
New MAF electronics (twice)
New MAP off mass air car (or BAP)
New TPS (twice)
New Fuel Pump
New FP filter
New ground strap
New 5 speed computer from advanced auto and an A9P auto computer
That's all I can remember right now.
Ok it seems like an electrical problem by the nature of me turning it off and on and it running fine. Here's some things I had questions about
#1: I rebuilt my tranny and for some reason put a top plate on the T-5 that didn't have the sensor on top. (not the reverse switch) The connector for it is just hanging under the car not being used. Now I'm not sure of the function of this sensor but I heard that it can cause similar problems if not connected or if the voltage isn't right.
#2 I heard that the B.O.O. switch can cause similar problems. (again I know this sounds crazy but very experienced people have told me this)
#3 My speedo gear keeps getting shredded (wrong one in tranny) so do u think it's because the speedo drive isn't turning? (i beleive i tried this once by putting a new one in and it didnt work)
#4 Should i try and find an original 5 speed ecu? Im pretty sure that A9p should work.
#5 Should I try a Pro-M meter?
#6 could I have gotten a bum injector that sticks or something until its de-energized by turning the key off and it runs fine until it sticks again?
#7 The ground that looks like it comes out of the injector harness; is that the injector ground or what?I have aluminum heads and it is grounded to them. (big ring connector)
I'm sure I can think of more later but if you guys could offer suggestions so far i'd greatly apprecitate it. I am sorrythis is my first post and it's so long but as you can see I've tried almost everything and I am at my wits end. this problem has stumped some of the best in the business so far.. Any help PLEEAASSEEE!!!?